MaplePrimes Posts

Latest Posts Latest Posts Feed

Congratulations to Eric Miles, a graduate teaching assistant at Colorado State University, for winning the second individual prize of The Möbius App Challenge! Eric will be receiving an iPad prize pack for his app Stretch and Translate Sin(x).

Maplesoft launched the Möbius App Challenge earlier this year to give Maplesoft community members the opportunity to get involved in the creation of Möbius Apps. This contest seeks to challenge users to create Math Apps using Maple, submit them to The Möbius Project website, then award the most useful, creative, and effective submissions. Finalists from the individual level challenge are chosen four times a year, so make sure to enter the next round of the challenge for your chance at a Maplesoft prize pack!

For full contest details and to enter, please visit: http://www.maplesoft.com/lp/mobius/index.aspx.

Jonny Zivku
Maplesoft Product Manager, Maple T.A.

Well-known problem is the problem of placing eight shess queens on an 8×8 chessboard so that no two queens attack each other. In this post, we consider the same problem of placing  m  shess queens on an  n×n  chessboard. The problem has a solution if  n>3  and  m<=n .

Work consists of two procedures. The first procedure  Queens  returns the total number of solutions and saves a complete list of all solutions (global variable  S ). The second procedure  QueensPic  shows the user-defined solutions from the list  S  on the board. Formal argument  t  is the number of solutions in each row of the display. The second procedure should be used in the standard interface, rather than in the classic one, since in the latter it may not work properly.

Queens := proc (m::posint, n::posint)

local It, K, l, L, M, P;

global S, p, q;

It := proc (L)

local P, k, i, j;

M := []; k := nops(L[1]);

for i in L do

for j to n do

if convert([seq(j <> i[s, 2], s = 1 .. k)], `and`) and convert([seq(l[k+1]-i[s, 1] <> i[s, 2]-j, s = 1 .. k)], `and`) and convert([seq(l[k+1]-i[s, 1] <> j-i[s, 2], s = 1 .. k)], `and`) then M := [op(M), [op(i), [l[k+1], j]]]

fi;

od; od;

M;

end proc;

K := combinat:-choose([`$`(1 .. n)], m);

S := [];

for l in K do P := [];

L := [seq([[l[1], i]], i = 1 .. n)];

P := [op(P), op((It@@(m-1))(L))];

S := [op(S), op(P)]

od;

p := args[1]; q := args[2];

nops(S);

end proc:

 

QueensPic := proc (M, t::posint)

local m, n, HL, VL, T, A, N;

uses plottools, plots;

m := p; n := q; N := nops(args[1]);

HL := seq(line([.5, .5+k], [.5+n, .5+k], color = black, thickness = 2), k = 0 .. n);

VL := seq(line([.5+k, .5], [.5+k, .5+n], color = black, thickness = 2), k = 0 .. n);

T := [seq(textplot([seq([op(M[i, j]), Q], j = 1 .. m)], color = red, font = [TIMES, ROMAN, 24]), i = 1 .. N)];

if m <= n and 3 < n then

A := seq(display(HL, VL, T[k], axes = none, scaling = constrained), k = 1 .. N), seq(display(plot([[0, 0]]), axes = none, scaling = constrained), k = 1 .. t*ceil(N/t)-N);

Matrix(ceil(N/t), t, [A]);

display(%);

fi;

end proc:

 

Examples of work:

Queens(5, 6);  

S[70], S[140], S[210];

QueensPic([%], 3); 

                                                                            248

[[1, 5], [2, 3], [3, 6], [4, 4], [6, 1]], [[1, 3], [2, 5], [4, 1], [5, 4], [6, 2]], [[2, 1], [3, 4], [4, 2], [5, 5], [6, 3]]

 

Two solutions of classic problem:

Queens(8, 8); 

S[64..65];

QueensPic(%, 2);

                                                                                      92

[[[1, 5], [2, 8], [3, 4], [4, 1], [5, 7], [6, 2], [7, 6], [8, 3]], [[1, 6], [2, 1], [3, 5], [4, 2], [5, 8], [6, 3], [7, 7], [8, 4]]]

 

 

Queens_problem.mw

There are still several bugs resulting from the MaplePrimes update last week which you may not be aware of.

  1. The list "All Recent Posts & Questions" is not in the correct order. It is ordered by the time of creation of the Post or Question. It should be ordered by the time of the most recent update to the thread. In other words, the top seven entries in "All Recent Post & Questions" should be the seven entries of "Active Conversations".
  2. Email notifications do not always contain a hyperlink to the relevant post. (I could send you some examples if you need.)
  3. In the list of Answers in a user's profile, the votes for the Answers are not shown for those Answers created after the update.
  4. There are no longer automatically generated titles for Replies for which the author fails to enter a title. This taken alone may be a good idea, but it contributes to bug (2) above. Also, it makes it impossible to send a "Contact Author" email relating to the Reply---when you click send on the email, it will be rejected, even if you tried to add a title.

MaplePrimes status...

October 25 2013 Bryon 1048 MaplePrimes

Earlier this week, we updated MaplePrimes with some fairly extensive changes that improved site performance. While MaplePrimes behaved as expected for most, a few people experienced some problems logging in, and a few other issues were also reported. If you are a MaplePrimes member inconvenienced by these issues, I apologize and thank you for your patience, and also for reporting the problems. I've had some conversations with a few different members, and your help in describing and diagnosing the problems is very much appreciated.

We have been working hard to resolve these problems, and I'm happy to report that most have now been taken care of.

  • The log-in function now works as expected across all browsers. If you are still having problems, you can visit http://www.mapleprimes.com/logout.aspx to force a log-out and reset your browser cookies for MaplePrimes, which will also correct the problem going forward.

  • We have corrected the problem where links to uploaded files were resulting in 404 errors.

  • We have also corrected an issue where the ordering of posts in a user's profile page was done incorrectly.


There are a handful of smaller problems that we continue to work through, and if you notice any other issues, please continue to let us know, either by posting here on MaplePrimes, or by contacting me directly.

Bryon

The board is going to work now with FF for me after latest updates.

NB: I got some mails advicing to delete (old) cookies for Mapleprimes, but
as my browser is alsways completely cleared on close (or on demand) that can
not have been the reason.

It works at least, if I give up all security settings. Which I do not want,
so I sketch a way to use them.

Be aware that not all in a page comes from Mapleprimes. Some is from another
server maplesoft.com and thus considered as 3rd party. Same for some scripts
and CSS etc, which stem from Google, jquery (or else)

If using NoScript or some blockers or similar essentially one has to allow
ajax.googleapis.com, which was needed in the previous version as well (see
below). Dito code.jquery.com is needed (both are 3rd party to Mapleprimes).

It still may hang up at loading ajax-loader.gif, which is located on the
server mapleprimes.com - I do not know why. After allowing a request policy
from mapleprimes.com to ajax.googleapis.com it loads.

That allows to still block all the social media stuff (especially FB connect
is disabled)

And currently I do not see calls to 2o7, just Omniture is trying to work.

---

For the call to Google: it seems to be needed only for their jquery library,
ajax.googleapis.com/ajax/libs/jquery/ and .../jquery/.

But the site calls the open source code.jquery.com/ui anyway. So why using
Google as well? Why not change and stay on code.jquery.com?

Calling to Google transmits my IP and browser header, it is like a fingerprint
and allows GG to identify me later on as Maple user. I dislike that very much.

Edited: edit works as well

So, I like Maple language. I want to promote it. However, among my friends, people mostly like things that are "Free and Open" like SymPy is. However, I think Maple is just better for mathematics, because it is so interactive, and it's so easy to explore mathematical concepts with it. So, I would like it to survive and be widely used.

The statistical R package seem to have survived by having many arduous open source fans writing packages, convenient functions and interfaces with general purpose languages. I don't see much of this trend with Maple, but I would love to, and yet I am not in power to change the fact that Maple is not open source. So, my question -- can we open source Maple?

After disabling all security addons the Ajax gif loads, then it shows an error and after that it jumps to a page displaying "2013", but that page actually does not have any content (use ctrl + u to see it).

And the I see, that the browser tries to load from maplesoft.112.2o7.net and hangs up in that transfer (have not checked the ports).

In reality I would forbid to load from 2o7, as I receject almost all trackers.

But looking at Adobe http://www.adobe.com/de/privacy/analytics.html or others http://www.makeuseof.com/tag/that-mysterious-2o7-net-tracking-cookie-all-you-need-to-know/ those are 3rd party cookies (Omniture ---> Adobe)

Every reasonable person aware of security and xss forbids dubious sources from other websites (and I am not happy that this sites call Ajax at Google)

And if that is the reason for the bad behaviour of the new sites it would be a good joke, really.

For me it only works with IE and all its security issues (and I have to use "preview" before posting is possible)

As of yesterday's updates to the MaplePrimes software, the ordering of the Answers in a User's Profile has been changed from reverse chronological to forward chronological. This sucks. If you have to change it, then at least make the ordering an option. I will note that the ordering of a User's Posts is still reverse chronological. It makes no sense for Posts to be in one order and Answers in another.

Also, I still cannot login on Firefox. I turned off all my add-ons, and it still doesn't work. It doesn't reject my credentials; rather it acts (for one screen) like it is logging me in as someone with a null name and 0 reputation.

When I edit someone else's material, it changes the author to me!!

In Internet Explorer, I need to update every page every time I view it. If I don't, I won't see the new material. 

I have not noticed any improvement in the amount of time it takes for updates to appear in the right column. It can still take a half hour from when the post/answer/reply was made.

Two problems surfaced when I upgraded my Mac to Mavericks (OS X 10.9).

First, the old Java SE installation was removed (actually, some linkages were destroyed), so a Maple launch puts up a dialog "need to install Java." Apple hasn't yet (10/23/13) updated the software database links --- installation fails with a "can't find software" error. I reinstalled Java using the version at http://support.apple.com/downloads/DL1572/en_US/JavaForOSX2013-05.dmg. (The links can be redone, it's just easier to reinstall.)

Second, the (new?) structure for /Library/Frameworks made my Maple license invalid. I dug out the old email with my activation code, then re-activated.

And all is now copacetic.

I can post answers, but those are not shown

PS: would have done at other threads - but as alreyd said ...

PPS: how about testing? grrrrrrrrrr .......

Earlier today, we posted an update to MaplePrimes that introduces some improvements, and also addresses a few issues. The most significant & noticeable improvements are speed related, and the performance of virtually every function/page on MaplePrimes has been improved dramatically.  The average increase is approximately 2x, but some pages (for example, Recent Questions or Unanswered Questions) benefit from much greater increases!

Other issues/enhancements include:

  • There was a problem where MaplePrimes would occasionally send multiple notification messages when a single reply/comment/answer was added to a thread that you are subscribed to. This no longer occurs.

  • MaplePrimes has been added as a clickable option under 'products' when asking a question or creating a post, and MaplePrimes-related topics are now grouped together.

  • The lag between when a new thread is created and when it appears in the right-hand side bar (this lag was often multiple minutes) has been eliminated. 
     
  • We added a data-integrity restriction such that if an answer or a reply has been added to a message, that original message can no longer be deleted. Formerly, the original author was able to remove their post, and subsequently all related comments, at any time.

There were a variety of smaller issues corrected as well.

We hit a couple of small bumps in the road during the implementation of the update (for example, there was a temporary issue where replies or answers didn't work), but we believe these have been taken care of. If you encounter any additional issues, please let us know.

We hope that these enhancements and fixes continue to make MaplePrimes more enjoyable to use, and I'm looking forward to your feedback!

Bryon

I can't post any Replies or Answers. It acts like they are being posted, but they just disappear. I've tried both in IE and Firefox.

I would like to Maple 18 has tabs and dropdown menus NO. So in this way the locations of the applications would be

Is there a specific reason why this web site (Mapleprime) is so slow? I have visited this number of times, since the early days it opened, and it is still as slow as the first day it was launched.

Just wondering. I think this extreme slowness of MaplePrime does not reflect good on Maple itself.

In addition, the line below the title of topics and questions, is always cut off in the middle. Fonts are not good, and the overall site, and entering text and code is very awkward to use.

Voting is open for the next individual prize to be awarded as part of the Möbius App Challenge.  The winner will receive an iPad Prize Pack! 

Here are the finalist Apps:

First 8 9 10 11 12 13 14 Last Page 10 of 225